Direct and indirect effects of pesticides on a benthic grazer during its life cycle

Environmental Sciences Europe

Table 2 Analysed terbutryn concentrations in the water phase at d_0, d_27, and d₆₈ in the different treatments under consideration of the SPE recovery rate of 87.2%

Sampling date	Terbutryn treatments (µg L⁻¹)
Sampling date	Control	0.006	0.06	0.6	6
d₀	–	< LOD	0.058	0.51	5.53
d₂₇	–	< LOD	0.040	0.39	4.54
d₆₈	< LOD	< LOD	< 0.030	0.28	4.19
DT₅₀ (day)	n.c.	n.c.	63 (r² = 0.98)	77 (r² = 0.99)	168 (r² = 0.88)
Effective concentration (µg L⁻¹)	n.c.	n.c.	0.040	0.38	4.72

The control stream was only analysed for terbutryn at d₆₈. DT₅₀s were calculated using a non-linear regression model with a first-order dissipation kinetic as reported by Brust et al. [12]. Effective terbutryn concentrations were calculated as geometric mean of all 3 sampling days. n.c. parameter not calculated, LOQ = 0.030 µg L⁻¹, LOD = 0.007 µg L⁻¹